The family of badly burnt toddler Arna Hopkins feel "cautiously optimistic" after the 3-year-old underwent surgery.

The Martinborough toddler was last night heavily sedated and on oxygen in Auckland's Middlemore Hospital after suffering burns to 50 per cent of her body on Monday.

She underwent a third surgery yesterday, which her uncle Kane Hopkins said went well.

"It's still very early, but I think cautious optimism is the thing. We are going into the weekend with that. She'll have more surgery next week, but it's all baby steps.

"It's still reasonably precarious, it's still nasty stuff. She's a very, very sick little girl but we are optimistic. And we are becoming very aware how long and slow this process is going to be."

Since arriving at hospital Arna has remained heavily medicated "in a comfortable state".

The toddler will likely stay sedated until her body can begin to cope with the surgeries and skin grafts.

"Every time she goes into theatre it's hard - it's stressful on her body, and there's complications with that."

Arna suffered severe burns to her body and face after accidentally setting fire to her clothes at her home.

She had been lighting a candle for twin sister Mila, who was born with Down syndrome and died of an infection last month.

The family had been lighting candles as part of their "memory times" for Mila, to help with the grieving.

Mr Hopkins said mother Penny remained by her daughter's side - "100 per cent" focused - while Arna's father, Regan, who badly burnt his hands saving her, is at home with their older children, Seb, 5, and Claudia, 6.

"He's still got serious, serious burns and he's still very painful. But he's hoping to be up here [to see Arna in Middlemore] next week."

Arna's next surgery is scheduled for Monday.

SUPPORT FOR ARNA

A Facebook page to support Arna Hopkins' family has been set up.

The page, named 'Support for Arna', was established on Thursday afternoon and had already yesterday received over 590 'likes'.

It has a link to the account where people can donate to the family, and was set up to support Arna in her recovery.

Any money raised will go to support the family throughout Arna's recovery.

Donations can be made at branches of the National Ban or by making deposits to: Support for Arna 06-0689-0298651-00.